Gene therapy, in which a viral vector is used to modify defective genes or replace missing ones, has shown significant potential as a way of treating disease in animal models. However its use in humans has been hampered by safety concerns. So researchers have been looking into the possibility of using nonviral vectors, which should carry fewer inherent risks, to deliver therapeutic genes.

In a paper published online this week by the Proceedings of the National Academy of Sciences, scientists from State University of New York report that silicon nanoparticles has been successfully used in mice.

Paras N. Prasad of the State University of New York (SUNY) at Buffalo and his colleagues manufactured nanoparticles using organically modified silicon. The surface of these particles can be tailored to target specific cells. The team used the tiny units to transport a fluorescent marker gene to dopamine neurons in the brains of mice. After injecting the nanoparticles, the researchers observed brain cells fluorescing using a new imaging technique that works on live animals. According to the report, the study is the first in which a nonviral vector has shown efficacy comparable to that of a viral delivery system in an animal model. A month later none of the animals had experienced adverse effects from the procedure.

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